The concept of on-the-go sod harvesters that can in a continuous operation cut a sod slab from a sod field and then stack the cut sod slab on a pallet, which can then be transferred to a work site by another vehicle, are known in the art. Typically, the sod harvester includes a set of knives that cuts a flat sod slab from the sod field. The sod slab, which may be left in slab form, is typically elevated upward from the sod field on a conveyor belt that discharges the sod slab onto a sod transfer mechanism. The sod slab is subsequently transferred to a sod pallet for further handling. The sod pallet with a stack of sod slabs thereon can then be transferred to a work site where the sod slabs are removed from the pallet and applied to the field. Examples of sod harvester for on-the-go harvesting are shown in Tvetene et al. U.S. Pat. Nos. 6,296,063; 6,783,318 and 6,364,027.
Occasionally, during the sod harvesting process the conditions of the sod soil may effect how the sod slab can be elevated from ground level to a location where the sod slabs can be stacked for delivery to a work site. Typically, the sod slabs are carried on a conveyor belt, which operates at an acute angle with respect to the horizon. Some times soil conditions cause the sod slab to slip on the sod conveyor, which can either jam the sod conveyor or cause damage to the sod slab. The failure of the sod slab to smoothly follow the sod slab conveyor requires operator correction and increases the time to complete the sod harvesting process as well as increases the spoilage due to a sod slab being damaged as the conveyor belt elevates the sod slab from ground level to the sod stacking mechanism in the sod harvester.